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#31
RK3188 / Re: [RK3328-SOM-EVB] Using UA...
Last post by cybernox - September 01, 2025, 04:57:33 PMI slightly modified the procedure because the armbian-config you included in the bookworm distribution doesn't have the DTC entry.
So I decompiled the rk3328-som.dtb file with the command
than edited the serial node serial@ff120000 switching from "disabled" to "okay"
recompiled the dts and updated the /boot/armbianEnv.txt file for using the modified version changing the line
fdtfile=rockchip/rk3328-som-mod.dtb
instead of
fdtfile=rockchip/rk3328-som.dtb
Now, when I boot
seems that the ttyS1 i recognized. I can open the port without errors but when I try to send out a string nothing exit from the TX pin. I used a digital oscilloscope to see if any signal i s present but the pin stay at high fixed level (3.3V)
Any suggestion?
So I decompiled the rk3328-som.dtb file with the command
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sudo dtc -I dtb -O dts -o rk3328-som.dts /boot/dtb/rockchip/rk3328-som.dtb
than edited the serial node serial@ff120000 switching from "disabled" to "okay"
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sudo nano rk3328-som.dts
recompiled the dts and updated the /boot/armbianEnv.txt file for using the modified version changing the line
fdtfile=rockchip/rk3328-som-mod.dtb
instead of
fdtfile=rockchip/rk3328-som.dtb
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sudo dtc -I dts -O dtb -o /boot/dtb/rockchip/rk3328-som-mod.dtb rk3328-som.dts
sudo nano /boot/armbianEnv.txt
sudo reboot
Now, when I boot
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sudo dmesg | grep ttyS*
[ 0.000000] Kernel command line: root=UUID=3440d0ff-bb26-49a0-92cb-65352124c942 rootwait rootfstype=ext4 splash=verbose console=ttyS2,1500000 consoleblank=0 loglevel=1 ubootpart=ec32f700-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory
[ 0.856367] ff120000.serial: ttyS1 at MMIO 0xff120000 (irq = 21, base_baud = 1500000) is a 16550A
[ 0.858993] ff130000.serial: ttyS2 at MMIO 0xff130000 (irq = 22, base_baud = 1500000) is a 16550A
[ 0.859126] printk: console [ttyS2] enabled
[ 7.750167] systemd[1]: Created slice system-getty.slice - Slice /system/getty.
[ 7.780739] systemd[1]: Created slice system-serial\x2dgetty.slice - Slice /system/serial-getty.
[ 7.841357] systemd[1]: Expecting device dev-ttyS2.device - /dev/ttyS2...
[ 10.293542] systemd[1]: Found device dev-ttyS2.device - /dev/ttyS2.
seems that the ttyS1 i recognized. I can open the port without errors but when I try to send out a string nothing exit from the TX pin. I used a digital oscilloscope to see if any signal i s present but the pin stay at high fixed level (3.3V)
Any suggestion?
#32
New Products release / Re: PICO2-XXL with RP2350 and ...
Last post by geerten - August 29, 2025, 04:23:47 PMHmm... There doesn't seem to be a section for Cerberus on this forum?
#33
New Products release / Re: PICO2-XXL with RP2350 and ...
Last post by geerten - August 29, 2025, 04:13:20 PMI don't think I could manage to solder that teeny tiny resistor, even if I had one.
Even some simple through-hole headers I can't seem to get straight...
I'll drop this for now. My Cerberus2100 arrived today. That should keep me busy for a while.
Even some simple through-hole headers I can't seem to get straight...
I'll drop this for now. My Cerberus2100 arrived today. That should keep me busy for a while.
#34
RK3188 / Re: [RK3328-SOM-EVB] Using UA...
Last post by LubOlimex - August 29, 2025, 01:26:38 PMYou can change configuration from the device tree files. Probably easier to edit using the Armbian tools. First notice that there are only 3 UARTs in this chip. Refer to page 414 of this document:
https://rockchip.fr/Rockchip%20RK3328%20TRM%20V1.1%20Part1.pdf
UART0 is used for the Ethernet, so you can't use it.
UART1 is free to use.
UART2 is the serial debug UART.
To enable the free UART1:
1. Do armbian-config
2. Go to system
3. Select DTC
4. In the nano editor press ctrl + W (to search) and find:
serial@ff120000 {
In the line where it says status = "disabled" change it to "okay"
5. Save and exit with ctrl + X and confirm to save the changes and to reboot the board. The serial should be enabled after reboot. I tested with simple wire between RX and TX of UART1 to see if I get echo - I do.
https://rockchip.fr/Rockchip%20RK3328%20TRM%20V1.1%20Part1.pdf
UART0 is used for the Ethernet, so you can't use it.
UART1 is free to use.
UART2 is the serial debug UART.
To enable the free UART1:
1. Do armbian-config
2. Go to system
3. Select DTC
4. In the nano editor press ctrl + W (to search) and find:
serial@ff120000 {
In the line where it says status = "disabled" change it to "okay"
5. Save and exit with ctrl + X and confirm to save the changes and to reboot the board. The serial should be enabled after reboot. I tested with simple wire between RX and TX of UART1 to see if I get echo - I do.
#35
NXP / Re: 1-Wire and 1.8 V on GPIO o...
Last post by ilario - August 29, 2025, 01:07:56 PMFantastic idea, thanks!!!
I will use the I2C and the SPI of the UEXT, but I am not planning to use the UART. So I can use the 2 UART pins from the UEXT
In the i.MX 8M Plus datasheet, I can see that the "ECSPI1_MOSI" AC20 and the "ECSPI1_SCLK" AF20 (exposed at the UEXT, after level shifting, as UEXT_TDX pin #3 and UEXT_RXD pin #4) have a pull down: "Input with PD".
For 1-wire seems that I have to use a pull up, do you think it is safe if I add a stronger pull up after the UEXT?
From the datasheet, seeeems that the pull-down resistor has a strength of 20-40 kOhm, so maybe I could add a pull-up of something like 2.2 kOhm? Does it sound like a good idea?
What still sounds like complicated is to use one of those pins with a DeviceTree overlay. I should free them from the UART3 before, right?
Should it be enough to set the UART3 to
Thanks!
I will use the I2C and the SPI of the UEXT, but I am not planning to use the UART. So I can use the 2 UART pins from the UEXT
In the i.MX 8M Plus datasheet, I can see that the "ECSPI1_MOSI" AC20 and the "ECSPI1_SCLK" AF20 (exposed at the UEXT, after level shifting, as UEXT_TDX pin #3 and UEXT_RXD pin #4) have a pull down: "Input with PD".
For 1-wire seems that I have to use a pull up, do you think it is safe if I add a stronger pull up after the UEXT?
From the datasheet, seeeems that the pull-down resistor has a strength of 20-40 kOhm, so maybe I could add a pull-up of something like 2.2 kOhm? Does it sound like a good idea?
What still sounds like complicated is to use one of those pins with a DeviceTree overlay. I should free them from the UART3 before, right?
Should it be enough to set the UART3 to
Code Select
status = "disabled";in the Device Tree?Thanks!
#36
RK3188 / [RK3328-SOM-EVB] Using UART1
Last post by cybernox - August 29, 2025, 12:19:11 PMI'm working with the RK3328 SOM (RK3328-SOM-EVB) and official bookworm downloaded from https://images.olimex.com/release/RK3328-SOM/RK3328-SOM-bookworm-minimal-20241127-120000.img.7z
I'm trying to enable UART1 but it's not working.
Here's what I have tried so far:
Enabled UART1 using armbian-config → rebooted, but the UART did not appear.
Created a custom Device Tree overlay targeting /serial@ff120000 and set the pinmux for GPIO3_A4/6 to function 5 → rebooted, but the UART still does not appear.
I created a dts inspired by the pinout in the datasheet
Then compiled
added mine in the file /boot/armbianEnv.txt
instead of the standard one that was
but nothing...
various diagnostic commands returns always the same result
output:
executed:
Output: disabled
Instead
give me the result okay (I suppose that this is the serial console uart, tested and working)
The command
return always
Output shows only ff130000.serial: ttyS2 (console/debug).
Despite these attempts, /dev/ttyS* does not show UART1, and the status of serial@ff120000 remains disabled.
Could you please confirm:
Which node corresponds to UART1 on the Olimex RK3328 SOM?
The correct pinmux/function settings for GPIO3_A4 (TX) and GPIO3_A6 (RX) for UART1.
Any known issues or additional steps needed to enable UART1 under Armbian?
Thank you very much for your help!
I'm trying to enable UART1 but it's not working.
Here's what I have tried so far:
Enabled UART1 using armbian-config → rebooted, but the UART did not appear.
Created a custom Device Tree overlay targeting /serial@ff120000 and set the pinmux for GPIO3_A4/6 to function 5 → rebooted, but the UART still does not appear.
I created a dts inspired by the pinout in the datasheet
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/dts-v1/;
/plugin/;
/ {
compatible = "rockchip,rk3328";
fragment@0 {
target-path = "/serial@ff120000";
__overlay__ {
status = "okay";
};
};
fragment@1 {
target = <&pinctrl>;
__overlay__ {
uart1_pins: uart1_pins {
rockchip,pins = <
3 4 5 /* TX -> GPIO3_A4, mode 5 */
3 6 5 /* RX -> GPIO3_A6, mode 5 */
>;
function = "uart";
};
};
};
};
Then compiled
Code Select
dtc -@ -I dts -O dtb -o /boot/dtb/rockchip/rk3328-uart1-olimex.dtbo rk3328-uart1-olimex.dts
added mine in the file /boot/armbianEnv.txt
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fdt_overlays=rockchip-rk3328-uart1-olimex
instead of the standard one that was
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fdt_overlays=rockchip-rk3328-uart1
but nothing...
various diagnostic commands returns always the same result
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ls /sys/firmware/devicetree/base | grep serial@
output:
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serial@ff110000
serial@ff120000
serial@ff130000
executed:
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cat /sys/firmware/devicetree/base/serial@ff120000/status
Output: disabled
Instead
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cat /sys/firmware/devicetree/base/serial@ff130000/status
give me the result okay (I suppose that this is the serial console uart, tested and working)
The command
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dmesg | grep ttyS
return always
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[ 0.000000] Kernel command line: root=UUID=3440d0ff-bb26-49a0-92cb-65352124c942 rootwait rootfstype=ext4 splash=verbose console=ttyS2,1500000 consoleblank=0 loglevel=1 ubootpart=ec32f700-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory
[ 0.865993] printk: console [ttyS2] disabled
[ 0.866687] ff130000.serial: ttyS2 at MMIO 0xff130000 (irq = 21, base_baud = 1500000) is a 16550A
[ 0.866814] printk: console [ttyS2] enabled
[ 6.976456] systemd[1]: Expecting device dev-ttyS2.device - /dev/ttyS2...
[ 9.592381] systemd[1]: Found device dev-ttyS2.device - /dev/ttyS2.
Output shows only ff130000.serial: ttyS2 (console/debug).
Despite these attempts, /dev/ttyS* does not show UART1, and the status of serial@ff120000 remains disabled.
Could you please confirm:
Which node corresponds to UART1 on the Olimex RK3328 SOM?
The correct pinmux/function settings for GPIO3_A4 (TX) and GPIO3_A6 (RX) for UART1.
Any known issues or additional steps needed to enable UART1 under Armbian?
Thank you very much for your help!
#37
NXP / Re: 1-Wire and 1.8 V on GPIO o...
Last post by LubOlimex - August 29, 2025, 10:25:04 AMThe pins at the UEXT of iMX8MPLUS-SOM-EVB are at 3.3V. We used translators for SPI and UART and transistors for I2C. Find the UEXT and look to the left to find the translators. If you decide to use GPIO1 pins (which are 1.8V levels) you can use the same translator SN74LVC2T45DCUR(VSSOP-8) to set them to 3.3V, use our usage as template on how we attached them to the signals of the UEXT.
These 8 pins can be used as GPIOs, according to the datasheet of the main chip they can be configured for GPIO usage. The pin #1 and pin #2 of UEXT are the power pins.
Notice that some of the pins at UEXT are inputs other outputs, there are pull ups, etc. This can be inspected in the EVB schematic again.
These 8 pins can be used as GPIOs, according to the datasheet of the main chip they can be configured for GPIO usage. The pin #1 and pin #2 of UEXT are the power pins.
Notice that some of the pins at UEXT are inputs other outputs, there are pull ups, etc. This can be inspected in the EVB schematic again.
#38
MSP430 / Re: MSP430-JTAG-TINY-V2 Window...
Last post by bcsmmc - August 28, 2025, 05:30:19 PMYou have to boot into the Troubleshooting screen, which means you need the bitlocker key and use option 7 to disable driver enforcement. Not sure about monthly updates, but you have to reinstall after a feature update.
1. Press the Windows key to launch the Start menu, click on the Power icon, press and hold the Shift key, and then click on Restart to enter the recovery mode in Windows 11.
2. Once the OS enters the recovery environment, click on Troubleshoot.
3. Next, click Advanced options.
4. Select Startup settings from the six options listed here.
5. Now, click on the Restart button.
6. If you are asked to enter the BitLocker recovery key, find out what to do. With the feature enabled, Windows may ask you to provide the key to ensure that no one else is accessing the data.
7. Finally, press the F7 or 7 key to boot Windows with the Driver Signature Enforcement feature disabled.
Once the system restarts, Driver Signature Enforcement will be disabled in Windows 11. You can now install the desired unsigned driver on your PC. To enable Driver Signature Enforcement in Windows 11, restart the computer.
1. Press the Windows key to launch the Start menu, click on the Power icon, press and hold the Shift key, and then click on Restart to enter the recovery mode in Windows 11.
2. Once the OS enters the recovery environment, click on Troubleshoot.
3. Next, click Advanced options.
4. Select Startup settings from the six options listed here.
5. Now, click on the Restart button.
6. If you are asked to enter the BitLocker recovery key, find out what to do. With the feature enabled, Windows may ask you to provide the key to ensure that no one else is accessing the data.
7. Finally, press the F7 or 7 key to boot Windows with the Driver Signature Enforcement feature disabled.
Once the system restarts, Driver Signature Enforcement will be disabled in Windows 11. You can now install the desired unsigned driver on your PC. To enable Driver Signature Enforcement in Windows 11, restart the computer.
#39
NXP / 1-Wire and 1.8 V on GPIO of iM...
Last post by ilario - August 28, 2025, 04:35:36 PMI am planning to use a iMX8MP-SOM-4GB-IND + iMX8MP-SOM-EVB-IND for replacing the A64-OLinuXino and having a modern Debian version.
With the A64-OLinuXino, I was using the GPIO for reading a few DS18B20 thermometers via 1-wire. I described what I am doing here: https://www.olimex.com/forum/index.php?topic=9266.0
The question is whether it is possible to do the same with the iMX8MP board as "Almost all signals have got voltage level of 1.8V!".
According to the DS18B20 datasheet, 1.8 V is not enough.
Do you have idea if using 1-wire will be possible?
Is there any GPIO pin I can use that already has 3.3 V or 5 V?
If all GPIOs are at 1.8 V, can you recommend me a level shifter from 1.8 V to 3.3 or 5 V?
With the A64-OLinuXino, I was using the GPIO for reading a few DS18B20 thermometers via 1-wire. I described what I am doing here: https://www.olimex.com/forum/index.php?topic=9266.0
The question is whether it is possible to do the same with the iMX8MP board as "Almost all signals have got voltage level of 1.8V!".
According to the DS18B20 datasheet, 1.8 V is not enough.
Do you have idea if using 1-wire will be possible?
Is there any GPIO pin I can use that already has 3.3 V or 5 V?
If all GPIOs are at 1.8 V, can you recommend me a level shifter from 1.8 V to 3.3 or 5 V?
#40
A64 / Re: 1-wire connection to DS18B...
Last post by ilario - August 28, 2025, 04:31:45 PMI added some guide at this page: https://linux-sunxi.org/1-Wire#Device_Tree